All posts tagged India Monsoon

“It has been observed that since 2001, places in northern India, especially in Rajasthan, are witnessing a rising temperature trend every year. The main reason is the excessive … emission of carbon dioxide.” — Laxman Singh Rathore, the director general of the India Meteorological Department.

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The reduction in India’s monsoon rains is a big deal. It generates systemic drought, creates a prevalence for heatwaves, and locally amplifies the impacts of human-caused climate change. For three years now, the Indian monsoon has been delayed. India is experiencing its worst heatwaves ever recorded and water shortages across the country are growing dire. The monsoonal rains are coming, again late. And people across India — residents as well as weather and climate experts — are beginning to wonder if the endemic drought and heat stress will ever end.

Historically, there was only one climate condition known to bring about a delay in India’s Monsoon — El Nino. And last year, a strong El Nino is thought to have contributed both to the Monsoon’s late arrival and to a very severe drought that is now gripping the state. What the 2015 El Nino cannot also account for is the 2014 delay and weakening of monsoonal rains. And during 2016, as India’s monsoon has again been held back by 1-2 weeks, and El Nino is now but a memory, it’s beginning to become quite clear that there’s something else involved in the weakening of India’s annual rains.

Indian Monsoon Delayed Third Year in a Row

(Onset of the Indian Monsoon has been delayed for three years in a row now. A condition likely caused by a human-forced warming of the world and one that is worsening an extreme drought and heatwave situation across the country. Image source: The India Meteorological Department.)

As of today, the eastern edge of the Southeast Asian monsoon had only advanced to the middle of Myanmar. This late progress is two weeks behind the typical advance of the monsoon in this part of the world at this time of year. Further west, the monsoon has extended somewhat futher — only trailing the typical monsoon’s advance by 5 days along the western coast of India.

With La Nina blooming in the Eastern Pacific, there’s no other climatological excuse for this delay. The El Nino influence is mostly gone. And all that’s left is a global climate context in which temperatures have now risen to around 1.3 C hotter than 1880s averages.

Climate Change is Likely Cause

Scientific studies modeling the impacts of human-forced warming have long found that heating the Earth atmosphere resulted in an eventual delay and weakening of the Indian monsoon. A study published last year in Geoscience Frontiers continued this line of study. Global Circulation Model (GCM) runs found that the Indian monsoon was expected to be delayed by 15 days on average during the 21st Century due to human caused climate change. That the amount of precipitation provided by the monsoon would be reduced by about 70 percent. And that the eastern section of the monsoon would tend to be subject to greater delays than the west.

(Extreme heat in the range of 45 to 51 degrees Celsius [113 to 124 degrees Fahrenheit] is expected to continue to impact a broad region of Northern India and Eastern Pakistan tomorrow. These temperatures are in record ranges and threaten to again break the all-time hottest temperatures ever recorded in India this week. By now, the onset of monsoonal rains should be taking the edge off a good portion of this heat. But a monsoon apparently delayed by a human forced warming of the world still holds back its cooling loads of moisture. Image source: Earth Nullschool.)

Delays in the Indian Monsoon result in a loss of precipitation due to the fact that the duration of the event is greatly reduced. Rainfall has to therefore be more intense over a shorter period of time in order to make up for losses. Increasing drought prevalence results in further moisture losses due to a kind of atmospheric heat and dryness barrier that tends to sap storms of precipitation even as they start to form. The net result for India is a prediction of severe moisture loss due to human-caused climate change.

This year’s India monsoonal delay — as with the delay during 2014 — falls into that pattern. And the massive drought that India is now experiencing as a result appears to be emerging from a set of atmospheric conditions that are consistent with human-caused climate change. India’s risk for continued drought and increasingly extreme heatwaves over the coming years is therefore on the rise. And it is yet to be seen if this year’s monsoon will deliver the hoped-for and desperately-needed relief. Already, the rain-bearing storm system is lagging. And that’s not a good sign.

The above May 25 temperature map by NOAA displays an extreme heat pattern that has remained in place now for weeks over India, with 40 degree Celsius (104 degrees Fahrenheit) temperatures covering a greater portion of the country. Andhra Pradesh, at the center of this hot zone, has seen the most impact with more than 1700 souls lost there as of this morning.

As with most heatwaves, the elderly, the poor, and those who work outdoors have shown the highest losses. In this heatwave, field workers, who survive on daily wages, have been particularly hard-hit. The choice for them has been a brutal one of brave the blazing heat and risk life or stay home in the shade and risk livelihood.

Monsoon Delayed, Weak

A smattering of rain showers has started to infiltrate sections of India as of today, bringing isolated relief. But, overall, the larger Indian Monsoon continues to hold off, delayed at its gates in the Bay of Bengal.

Unfortunately, due to the delayed monsoon and extreme heat deeply entrenched throughout many regions of India, we can expect a high risk for loss of life to continue for at least the next few days as a weakened and delayed monsoon fights to gain ground. This is an instance of yet another early, easy outlier of the very extreme climate change related weather that will follow, with locked-in conditions worsening so long as we continue burning fossil fuels.

El Nino has yet to be declared. Though signs of the Pacific Ocean warming event abound, they are still in the early stages. But for all the impact on the current Indian Monsoon — the rains this vast sub-continent depends on each year for a majority of its crops — the current pre-El Nino may as well be a monster event comparable to 1998.

Through June 25th, the trend of abnormally frail monsoonal rains continued unabated:

(India cloud cover on June 25, 2013 [left frame] compared to India cloud cover on June 25 of 2014 [right frame]. Note the almost complete lack of storms over India for this year compared to 2013 when almost the entire country was blanketed by rains. Image source: LANCE-MODIS.)

India’s Rain Pattern Has Changed

It’s not just that 2014 is a bad year for India. It’s that the current weakened monsoon comes at the tail end of a long period in which the rains have increasingly failed. Where in the past it took a strong El Nino to stall the rains, ever-increasing human atmospheric and ocean warming have pushed the threshold for Monsoonal failure ever lower. Now even the hint of El Nino is enough to set off a dry spell. A growing trend of moisture loss that is bound to have more and more severe consequences.

A new study by Stanford University bears out these observations in stark detail. For the yearly monsoon that delivers fully 80 percent of India’s rains has fallen in intensity by more than 10% since 1951. And though a 10% loss may seem relatively minor, year on year, the effects are cumulative. Overall, the prevalence of dry years increased from 1981 to 2011 by 27% and the number of years experiencing 3 or more dry spells doubled.

Meanwhile, though a general drying trend has taken hold, rain that does occur happens in more intense bursts, with more rain falling over shorter periods. These newly intensified storms are more damaging to lands and homes, resulting in both increasing destruction of property while also greatly degrading the land through more intense erosion.

25 Percent of India’s Land is Turning to Desert

Loss of annual monsoonal rains is coming along with a dwindling of water flows from the melting Himalayan glaciers. These two climate change induced drying effects are already having stark impacts.

For according to the Indian Government’s Fifth National Report on Desertification, Land Degradation and Drought, a quarter of India’s land mass is now experiencing desertification even as 32 percent is suffering significant degradation due to heightening dryness and erosion. This amounts to more than 80 million hectares of land facing desertification while more than 100 million hectares are steadily degrading. The report also noted that areas vulnerable to drought had expanded to cover 68% of the Indian subcontinent.

Desertification and loss of biological potential will restrict the transformation of dry lands into productive ecosystems. Climate change will further challenge the livelihood of those living in these sensitive ecosystems and may result in higher levels of resource scarcity.

By today, June 26, the long disrupted and weakened monsoon continues to sputter. Moisture flow remains delayed by 1-2 weeks even as the overall volume of rainfall is greatly reduced. Though storms have exploded over some provinces, resulting in flash flooding, much of the country remained abnormally dry. Overall, preliminary negative rainfall departures remained at greater than 40% below average for most of the nation with only five provinces receiving normal rainfall and the remaining 31 receiving either deficient or scant totals.

Current advance of the Indian Monsoon indicated by the green line vs typical historic advance indicated by the dashed red line. Image source: India Meteorological Department.

The Indian Monsoon arrived in Sri Lanka on June 2nd, 8 days late, with extreme force. Dumping excessive rainfall even for a typically powerful event, it forced 2,500 to flee and resulted in the loss of 22 souls. There it stalled, battening into a Bay of Bengal moisture flow that hasn’t budged since May 23rd.

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By today, June 5th, powerful storms should be dumping rain over a wide swath including the entire southern tip of India, almost all of the waters between Myanmar and the Tamil Nadu and Andhra Pradesh coasts, and over most of Bangladesh. But in the satellite shot only scattered storms are visible where powerful, wall-to-wall squalls should now cover an impressive swath.

By this time last year, more than a third of India was obscured by cloud. Today, the skies of this nation of 1.25 billion people are ominously clear. The steely-gray aerial tint of coal ash smog is the most impressive feature in an otherwise open expanse from the northwest deserts to the southeast coast. A massive zone showing only sparse hint or hope of rain.

Even Sri Lanka seems mostly cloud-free. The monsoon and, more importantly, the crop-essential rains it brings are walled out, pushed into the margins by El Nino and some of the hottest global temperatures on record.

Blazingly clear skies laced with ominous coal ash over India during a time when monsoonal storms usually advance. Image source: LANCE-MODIS.

Forecasts indicate that some of the long-delayed rain could arrive to the coast by tomorrow through Sunday. Sparse comfort to sweltering interior sections that may not now see the cooling monsoon until after July 1st.

Unrelenting Heat Risks Late Switch to Violent Storms

In the north, the heat and drought just builds and builds. Jaipur recorded its highest temperature in 33 years on Thursday at a scorching 46.3 degrees Celsius (115.3 F). Meanwhile, New Delhi hit a new record high for the day of 45 C (113 F). Forecasts for New Delhi on Saturday and Sunday show the potential for even more extreme heat with temperatures projected to climb to 116 F. Over the coming ten days, the coolest is expected to be Friday of next week at 109 F.

The continued delay of monsoonal rain combines with record heat throughout northern and western sections of India to enhance risks of drought and loss to crops. Heatwave conditions have already reduced Lychee fruit crop yields by 40%. But an extended stalling of the monsoon and ongoing heat could result in increased damage.

Atmospheric thickening that comes with such extreme heat can also spur intense rain and hail events causing another kind of damage to crops. So a flash switch from heat to heavy storms like those seen earlier this week in Sri Lanka may not be so much of a boon as a terrible jolt to affected lands.

Moderate to Strong El Nino Ever More Likely

This year’s monsoonal delay and related extreme weather were likely amplified by a combination of record atmospheric heat due to human-caused greenhouse gas forcing and a growing and strengthening El Nino. In April, global atmospheric temperatures hit new record highs of +.91 C above 1880s values even as El Nino rapidly gained ground in the Pacific through May.

Multivariate ESNO Index values catapulted to +0.93 in May hitting the seventh highest values on record for the month and pushing the current El Nino into Moderate-Strong range for this time of year. During previous years, similar high values resulted in strong El Ninos on 3 of 5 occasions in the climate record. So historical indicators point toward a 60% chance of a strong event emerging by later this year.

The long anticipated breakthrough to El Niño conditions in 2014 is clearly under way, leading to the next question of how big it will get. Of the 10 nearest-ranked April-May values, five had clearly come up to this level over the previous three months. Among those five, four continued at El Niño levels through the rest of the year, while one (1993) dropped back to borderline neutral conditions by the end of the year. One (2002) ended up as a weak-to-moderate event, while the other three (1957, 1987, and 1997) are classified as strong El Niño events in the MEI sense. In other words, the simple-minded odds for El Niño remain at or above 80% through the remainder of 2014, and are consistent with previous discussions on this website. The odds for a strong El Niño are perhaps slightly higher than before, somewhere around 60%.

Meanwhile, the official NOAA forecast is more cautious, with model interpretations pointing to a higher likelihood for a moderate El Nino during 2014.

Overall, chances for evolution to full-blown El Nino rose significantly with today’s forecast now showing a 70% chance for El Nino development by this summer and nearly an 85% chance for El Nino development by Fall-Winter.

Regardless of El Nino strength, such an event is likely to have broad-ranging global impacts in the context of human-caused warming.

India’s Heightening El Nino + Climate Change Threat to Crops

For India, history shows numerous cases of severe monsoonal disruption during strong, moderate, and, recently, even weak El Nino events. In addition, record high atmospheric temperatures enhance extreme drought and flood potentials by amping up the hydrological cycle and thus increasing the rate of both evaporation and precipitation. Storms, where they do occur tend to be both tall and abnormally powerful under current human-warming related stresses even as droughts tend to develop with higher velocity and to persist for longer periods.

It is possible, due to both changes to the hydrological cycle and to atmospheric circulation, that the Indian monsoon has become even more sensitive to the El Nino pattern under current human-caused warming. This year’s monsoonal delay with El Nino just emerging shows an almost instant response to the forcing coming from increased temperatures in the Equatorial Pacific. As such, conditions of heightening threat for crop damage throughout a land where 1.25 billion people rely on the annual rains is a critical issue.

(Extraordinary sea surface temperature anomalies in the Northeast Pacific including numerous pools of +2.25 to +4 C or higher departures are indicative of both a strengthening El Nino pattern and a general warming of Ocean surface waters through human greenhouse gas heat forcing. Image source: NOAA Environmental Modeling.)

Overall, the forecast remains for continued monsoonal delay and disruption, continued heatwaves and a likelihood for extreme rainfall and storms in the regions where the monsoon finally arrives. With El Nino conditions in place over the Pacific now, with atmospheric temperatures rising into record range, and with an official El Nino status likely to be declared by summer, this forecast is lent yet more certainty and urgency.

May is the month when the massive rainstorm that is the Asian Monsoon begins to gather and advance. This year, as in many other years, the monsoon gradually formed along the coast of Myanmar early in the month. It sprang forward with gusto reaching the Bay of Bengal by last week.

And there it has stalled ever since.

On May 25-27, an outburst of moisture from this stalled monsoonal flow splashed over the coasts of India. But by the 29th and 30th, these coastal storms and even the ones gathering over the Bengali waters had all been snuffed out. The most prominent feature in the MODIS shot of India today isn’t the rainfall that should be now arriving along the southeast coast, but the thick and steely-gray pallor of coal-ash smog trapped under a persistent and oppressive dome of intense heat.

(MODIS shot of India on May 30th. See the open stretch of blue water in the lower right frame? That’s the Bay of Bengal which borders coastal India. During a normal year at this time, that entire ocean zone should be filled with the storm clouds of a building monsoon that is already encroaching on coastal India. Today, there is nothing but a smattering of small and dispersed cloud through a mostly clear sky. Image source: LANCE-MODIS.)

Monsoon Described as Feeble

Official forecasts had already announced as of May 27th that the annual monsoon was likely to be delayed by at least a week for southeast regions of India. Meanwhile, expected monsoonal rainfall for western and northern sections of India for 2014 fell increasingly into doubt.

The monsoon is likely to be delayed by 10 days, according to scientists at the Indian Institute of Tropical Meteorology (IITM) here. The IITM’s third experimental real-time forecast says that a feeble monsoon will reach central India after June 20 as against the usual June 15. Last year, the monsoon had covered the entire country by June 15.

The annual monsoon is key to India’s agriculture. The substantial rains nurture crops even as they tamp down a powerful heating that typically builds throughout the sub-continent into early summer. Without these rains, both heat and drought tend to run rampant, bringing down crop yields and resulting in severe human losses due to excessive heat.

But, this year, heat and drought are already at extreme levels.

Major Heatwave Already Results in Loss of Life for 2014

As early as late March, the heatwave began to build over the Indian subcontinent. The heat surged throughout the state, setting off fires, resulting in a growing list of heat casualties, shutting down the power grid and spurring unrest. Meanwhile, impacts to India’s agriculture were already growing as the Lychee fruit crop was reported to have suffered a 40% loss.

By late May, temperatures across a broad region had surged above 105 degrees shattering records as the oppressive and deadly heat continued to tighten its grip.

In a country surrounded on three sides by oceans, it is a combination of heat, humidity and persistently high night-time temperatures that can be a killer. Wet bulb temperatures surge into a high-risk range for human mortality during the day even as night-time provides little respite for already stressed human bodies. Such extreme and long-duration heat doesn’t come without a sad toll. As of today, early reports indicated a loss of more than 56 lives due to heat stroke (In 2012 and 2013, total Indian heat deaths were near 1,000 each year). That said, final figures on heat losses are still pending awaiting complete reports from all of India’s provinces.

“Climatologically, we know that heatwaves are increasing in frequency and the number of days exceeding 45ºC temperatures is increasing. The frequency will increase further with global warming, hence this is a good example of a situation where science and disaster management can come together and avert damage,” a spokesman for India’s National Disaster Management Authority noted on Friday.

Today the heatwave continued to gain ground, with Kota and Rajasthan reaching an all-time record of 116 degree F (46.5 C) as New Delhi’s mercury hit 113 degrees F in the midst of a drought-induced dust storm. Dust shrouding the city spurred traffic chaos and in the heat, darkness, and confusion nine more souls were lost.

After two months of growing disruption due to heat and drought, the lands and peoples of India cry out for a Monsoon that is running later and later with each new weather report.

Climate Change + El Nino: Adding Heat and Beating Back the Monsoon

As systems approach tipping points, they are more likely to tilt toward the extremes.

For India this year, its seasonally warmest period from April to May found severe heat amplification from a number of global factors. First, climate change seeded the ground for the current Indian heatwave by adding general heat and evaporation to already hot conditions. With global average heating of +0.8 C above 1880s levels amplifying in the hot zones, early moisture loss due to higher-than-normal temperatures produces a kind of snowball effect for still more warming. Essentially, the cooling effect of water evaporation is baked out early allowing for heat to hit harder just as typical seasonal maximums are reached.

In addition, this year saw rapid progress toward an El Nino event in the Pacific Ocean with sea surface temperatures warming into the El Nino range by mid-May and continuing to ramp higher. By today, Equatorial Pacific anomalies had hit +0.63 C according to GFS analysis, extending a run into El Nino conditions.

El Nino events typically allow for the formation of hot, drier air over India. These air masses tend to engender extreme heatwaves like the one we are seeing now even as they delay the onset of cooling monsoonal rains. In essence, the monsoon is confronted with a heavy and entrenched wall of hot air that doggedly resists being shoved aside. And this is the very situation we observe now over India — a sputtering monsoon to the east getting bullied by a brutally hot and thick air mass that just won’t give ground. Climate change only exaggerates the problem by increasing the intensity and inertia of the hot air mass.

Major monsoonal disruptions typically occur during years following an El Nino’s peak heating impact. For example, in 1998, during a period following an extreme El Nino, India suffered one of its most severe droughts and monsoonal delays on record. But during recent years preceding El Nino, such as 2009, India also saw severe heat, drying, and crop damage due to a weakening of the annual summer rains. So an early monsoonal enfeeblement and coincident strong heatwaves and droughts over India with El Nino still forming is cause for some concern and bears further monitoring.

Currently, temperatures over India are surging to between 5 and 12 degrees Celsius above already hot averages. With heat and drought firmly in place, forecasts are calling for a 1 to 2 week delay in the cooling and moisture-bringing monsoon as India continues to swelter.